Left behind retention actor
by NothingToAddHere
Summary: After Allen left the Order for roundly half a year and Kanda being promoted to General rank, Professor Dumbledore, current Headmaster of Hogwarts, reported to Black Order for some strange events that even stranger than magic, suspected Innocence-related happening in the school and asked the Black Order to investigate. Book 5 and chapter 217. Rate T just to be safe.
1. Chapter 1

A/N: both series in this crossover fanfiction take place at the same time, just for the sake of plot convenience.

Here we go, another one using the most cliché starting-storyline ever for a HP-DGM crossover fanfiction as Professor Dumbledore, current Headmaster of Hogwarts School of Witchcraft and Wizardry, reported to Black Order for some strange events that even stranger than magic, suspected Innocence-related happening in the school and asked the Black Order to investigate. Story time's set: Book 5 and chapter 217 (in DGM case, only for Kanda's promotion to a General).

Please beware of weird English.

* * *

Chapter 1: Sides

Lenalee was simply sitting on her comfy bed, wearing only thin clothes hugging the pillow, eyes closed as if they were sleeping. Her room's door-sized glasses window was left opened, allowing afternoon's breeze to breathe in

Summer meant dazzling sun, noisy cicadas, burning heat and endlessly deep blue sky.

Despite the hot, Lenalee let her hair down.

Her hair had grown to her chest, like time flew. It had been half of the year since the day her white-haired friend went missing. The Order tried its best to find him, but received no result. Things were slowly changing after that. Master Zhu passed away. Kanda became a General, still in training though. Johnny no longer lived here in the Order.

Before anyone could have recognized, a lot of things had changed. But, at the same time, there were things remained unchanged.

Ones of them were her hope of everyone being able to reunite and laugh like how they used to be and the belief that a certain friend of her still stood on the same side. As long as those continued existed, Lenalee wouldn't mind her fate to fight this war possibly until death.

How she wished, to find some traces of her friend.

"Lenalee, can you head to the Command room? There is a mission I want to discuss."-Said her brother via the little flying wireless communication golem.

Hearing so, the girl got up and replied with a smile.

"Okay, big brother."

Summer was going to end soon.

After completed changing to her uniform, Lenalee followed the corridor way to her brother's filled-with-unfinished-paper-works messy room, only to found Kanda had already been there sitting on the couch with his usual growling face.

"Komui goes to call Timothy and Chaozii, it seems those two are without their golems. You are called too?"-Asked Kanda.

"U-uhm. You too?"

[Nervously answered.]

"Isn't it obvious that I am?"-Kanda replied, looking away as Lenalee had her seat next to him. Both of them sitting there on the striped couch looked opposite directions in silence.

[Awkward moment.]

"This won't lead to anywhere", Lenalee sighed.

"What?"

"Nothing."

Kanda stared at Lenalee for a moment.

"Your hair is long again huh?"

"Hair cannot be short forever."- Lenalee stretched her arms-"And I have no intention to get it cut."

She smiled.

"But, Kanda, can I ask why you don't cut your hair?"

"If I survive today after Komui saw me sitting with you, I will consider it."

"I'm pretty sure you can make it somehow, Kanda."

Hearing her brother's voice, Lenalee felt her heart almost stopped. Kanda, however, was not amused. Timothy was trying his best not to laugh and Chaozii just stood there speechless.

"You scared me, big brother."-the girl said as she held her breaths.

Komui walked to his desk, adjusted his glassed.

"As long as I live, I won't allow any hands lay on my precious little sister. We will talk about this later. Now, about the mission for all of you…"

"Four of us in one mission? Is that a little too much in our current Exorcist-shortage situation?"-Chaozii asked in his surprised.

"We have had a serious discussion. Moreover, this will be the Kanda's first mission in his General status, so he would need all help possible. We can't afford losing another General."

"If that's the case, then why choose me and not a more experienced Exorcist, like Marie for example?"-Timothy questioned, crossing his arms in confused.

"Because this mission takes place in a school named Hogwarts, and everyone here is the closest to the student's accepted ages, which is from eleven and seventeen years old. I will have the school's Headmaster, Professor Albus Dumbledore, explain more specifically. We have arranged a meeting for you guys tonight. What happens after that will be on Kanda's decision. But personally, I am really looking forward to a good harvest this time." Komui continued.

"I'm going to lose my patience here. Can you give us more detail? This is unlike you."  
-Chaozii said, annoyed by Komui's vague answer.

Hearing Chaozii's growls, Komui calmly explained with a smile:

"It's not like that I don't want to give you more information, but I am not someone who can answer all of your possible questions about this mission as there are things I don't understand myself yet I think you guys have ability to judge."

"Well, if you said so…at least mind giving us the place and the time of the meeting?"-Lenalee signed.

Chaozii was right. Her brother had never been like this.

"Ah yeah. Professor Dumbledore will pick you up in front of a pub called Leaky Cauldron, which locates on Charing Cross Road by 18:00. We will take you there by horse carriage after using the Gate no.31 by 16:00, so pack up all you need, since this won't seem to be a short mission."

"Wow, that's hurry. Fine to me, then, as long as Emilia isn't around and I don't have to study."-said Timothy as he lazily left.  
"Well, if it can keep me to continue fighting with the evil then I guess it can't be help."- Said Chaozii.

Kanda followed the two to the door and gave no words.

"Lenalee, can I talk to you a bit?"

Hearing her brother's call, Lenalee turned back just right she was ready to leave.

"Yes?"

"About Kanda, can you keep a close eye on him for me? Central has put a lot of unnecessary stress on him and he is quiet lately. I don't know what happened during his General training so I think it's best to pay attention."

The girl smiled.

"I promise. We're off, then. Please take care of yourself."

"I will. Take care of yourself, too."

[Brother and his little sister's moment.]

Lenalee closed the door.

Meanwhile, in Hogwarts, more accuracy, in its Headmaster's office, which was filled by all sort of portraits hung across the room with people moving inside wood frames, books, a lot of books and old paper scrolls, various of strange magic tools here and there, a middle aged wizard in his formal gray silk robe walked anxiously around the couch, only stopped and turned himself to the old one standing firmly behind when he started talking.

"So…you're saying the Ministry is going to infiltrate Hogwart, Mr. Fudges the Minister?"

"Not infiltrate, Dumbledore. If you do nothing wrong, we will just be silent stones by the street. You created troubles for us there with your babbling about You-Know-Who's return and Potter's underage magic law violation case after that."

"It was you that exonerated the boy." The old wizard voiced up, cutting Cornellius Fudge's line.

"Yes, I am. And don't make my regret it."

RIIING!  
[Sound of bell ringing]

Fudge hopped in fear hearing the sound.

"W-WHAT WAS THAT?"

Dumbledore slowly stepped to his desk, where the sound coming from, picked up the handset.

"Oh this? This is a sound transmitter device invented by Muggles. They called it 'telephone'. This one is able to function in Hogwarts because I use magic to have it works. Hello, this is Hogwarts's Headmaster office. May I ask who this is?"

"Long time no see, professor. This is me."

[A girl's voice]

"Oh, it's nice to hear your voice again. I thought you were really busy there."

"Indeed I was, busier even than ants. But there are changes in circumstances therefore I have plenty of free time now. It is fine if I pay a little visit to my old school?"

"I see no problem for an old student of Hogwarts returning to this place. Feel free to drop by and call me when you arrived. You were one of those 'special' students back then."

In the other side of the phone, the dark-haired girl pulled out a grin.

"Okay then, I think I may get to Hogsmeade around a month later. Please have a good day."

"I'm looking forward to it."

"You aren't."

[Phone hanged up]

"W-who was it?" –said Fudges, who was trembling like seeing the world's apocalypse.

"Oh my, I am really sorry for my rudeness leaving you there. And for your question, she is an old student, a really clever and sharp one, with exceptionally great talent, when not used for pranks, but I guess everyone have their youthful time."

A flash of the students laughing around him while they were trying to find out which color his socks was slipped in his mind.

[Good old memories]

"I-I don't care."-Fudges gathered his strength and snarled-"Just know your place, Dumbledore."

The door was slammed shut violently.

"Everyone has their doubtful time, too I think."

Fawkes the phoenix flew by the side of the Headmaster, poking him.

"Oh dear, look at the time. I have another guess to see."

[Charing Cross Road]

"We are really sorry, but we can't find any pub called Leaky Cauldron in this road."

The Finder said confusingly.

The Exorcists group was standing by their horse carriage on the street. The blazing sun was going down, colored the whole sky red.

"But Komui said the appointed-place was in this street."-Timothy growled.

"Yet we can't find it anywhere. Is this somekind of trap?"-Said Chaozii.

Lenalee sighed. The girl hoped there wouldn't be something bad behind. She looked up and saw a small gray building in the other side with off-designed compare to the rest. The building looked dulled and pretty much old. A black square iron sign of witch-lookalike using broom swirling a cauldron was hung hover the entrance.

[Leaky Cauldron]

"Is there something? Lena-"

Kanda stopped his words as Lenalee pointing up ahead, across the street.

"There, between the bookshop and the record store .Leaky…Cauldron, right? We found it."-Said Lenalee.

"What's wrong, miss Lenalee?"-Asked Chaozii.

"We found the Leaky Cauldron."-Said Kanda.

"The sign looks like to be a cauldron, I am not sure about the 'leaky' part." – Said Timothy.

"But sir Exorcist, all we can see a broken-down old shop…"

The Finder was even more confused.

"Eh?"

"We are the only ones who sees it? It's clearly a trap now." –Said Chaozii.

"Yes you are, but the place is not a trap." – An old man's voice appeared, making the Exorcists team shocked due to the surprise.

Before them was a very old tall and thin man with hair and bread which is as white as concrete and long enough to be tucked inside his belt standing right behind them. The soul-piercing blue eyes under half-moon spectacles gazed at the group. He smiled gently and said:

"My apologies for getting late. You are Exorcists of the Black Order, if I'm correct?"

Still being confused, the team restrained their words, looked at the old wizard with doubt.

"Well, only beings related to magic can see the most famous wizard pub in London. Normal human can't, however."

Dumbledore switched his look to the finder, still smiling.

"Wait, wizard? They are real?"-Chaozii said in amazed.

"…."  
Kanda commented nothing, while Lenalee reminded herself when she was stuck with General Cross in the Ark.

"And you are…"-said Kanda.

"People call me professor Dumbledore."

[The name was given correctly]

"He is not lying."

[Cheerfully said by Lenalee]

"How would you know?" –Said Timothy.

"I just know."

"It's getting late. Why don't we get inside?"

The four Exorcists looked at each other for a moment. Lenalee turned to the Finder, said:

"We will take care of it from here. Thank you for taking us here."

"A-are you sure, miss Exorcist?"

"I think we can trust this person, beside, there are four of us. If something may go wrong, we will work it out nicely."

The girl smiled at the finder.

"I see, please be careful, then."

"See you later."

The four followed Dumbledore to the pub after the Finder left. Despite the cold and grubby look, the inside was unexpectedly warm.

"What a surprise seeing you here, Professor. On what possibly occasion is this?"

An bald old man approached them, introduced himself with the group as the place's owner, Tom.

"I just get my unusual guests. May I ask for a room?"

"My pleasure, Professor. Are those kids with you?"

"Yes, they are my guests."

Dumbledore said, smiled at the group of Exorcists, who were gluing their eyes on how strange the pub looked to them, with wood tables and chairs adjusted themselves and such.

The summer's august was going to end soon.

Meanwhile, in Hogwarts, a lone boy wearing the black school's uniform robe was sitting in the stone banister, watching the sun set, hood on. He was small, and looked no older than 12. A shining silver birdie was standing on his shoulder. The wind was blowing hard.

"I can hear it… Brought by the wind is annoying noise of those cursed machines coming from Hogsmeade village."

The wind blew off his hood, revealing the white short hair and an uninterested face with silver eyes.

"What to do now…"


	2. Chapter 2

A/N note:  
Thank you for supporting this little piece. I am very grateful.

TOOLAZYTOLOGIN: Thanks for the review. The answer is…both yes and no. Please continue following the story to find out :D  
Guest & Time to Be: Thanks for the review. I'll try my best.  
Disclaimer: I do not own both DGM and HP.

Chapter 2: Destroy the fear

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There was a party at 12 Grimmauld, not really big one, just a larger-than-normal dinner. The room was decorated cheerfully enough to shoo away the house's dining room gray gloominess, as how colorful paper letters floating and jumping around the room, forming a sentence "CONGRATULATION ON BECOMING PERFECTS". Everyone, both adults and soon-adults, were happy while enjoying 's delicious dishes.

Come on, who wasn't happy any chance possible, especially in the time of era, when you could be killed a minute later by You-Know-Who.

Of course, Harry Potter was happy too. Two of his best friends, Ron Weasley and Hermione Granger, became Perfects, which meant their abilities had been acknowledged. What more he could hope for?

_You can hope for better._

Not this again.

He had had enough with his-probably- stomach clenching every time he thought of this despite having stuffed with unspewable food. The boy silently left his seat, trying not to get anyone's notice. Unfortunately, without his Invisibility Cloak, the poor Potter couldn't get away the mischievous Weasley Twins.

"Going somewhere, Harry?"-Asked Fred, or George, one of the twins, as he grabbed Harry's neck from behind in surprise.

"Let me go, I just need the toilet"-Harry replied. The kid was walking down the hallway, dragging the much-bigger-than-him twins.

"Don't worry, it's fine. If you need interesting news that much, just ask and we can generously share anytime!"

"I already know Voldermort is recruiting and trying to find a certain weapon, but thanks anyway."

"We didn't tell Ron or anyone everything we got thanks to our Extendable Ears and it seems something nasty was going on in Hogsmeade."

"Okay, that is new. Is it Death Eaters-related?"

"No one is sure. Reports say there was some kind of monstrous creatures attacking some people there. No one was seriously hurt, but poisoned. Those two victims were transferred to and we heard that they are well and alive. Witnesses said the creature was Muggle weapon-like, with canons and gears pointing out of their body so…the Order doesn't think they are Voldermort-related."

"Voldermort hates everything Muggle-related. But who knows, maybe he gives up his arrogant and desires such weapon."

The three young wizards turned around hearing the voice, to found out Lupin and Sirius was behind them, giving out the "youngsters these days" mixed with ironical pride look.

Hearing the words, Harry said:

"I'll be careful then."

Lupin grabbed Harry's shoulders, so hard the kid felt little hurt.

"No, Harry. You're slightly taking this matter. There are people specializing on this living weapon and they are not you. They're going to arrive here soon and leave this to them. We may become weight on their job."

"We planned to announce and explain this stuff with all of you once Mad-Eye led them here. But those Extendable Ears are amazingly well-made."

Harry could see the twins smile with pride without looking.

"NOOOOOOOOOOOOOOOOOOOO!"

An extremely loud, high-pitched and painful screech of scream could be heard by everyone inside the house, making hearts of who didn't aware of the screamer enough jump 5 feet away from their chest.

"Oh no. It's her."  
Sirius tiredly lamented.

"MUDBLOODS! SCUM! BLOOD TRAITORS! FILFTHY CREATURES IN OUR NOBLE HOUSE! WHAT CURSE ON EARTH IS ABLE TO PURGE THIS DISGRAFUL SHAME!"

Lupin rushed to the front door, meanwhile, Sirius headed to the Walburga Black portrait-where the scream came from. The Weasley Twins dragged Harry with them and followed Lupin, as they said "Are you not curious about these 'specialists'?".

Harry wanted to answer 'No', however. Not so long after, Hermione and Ron joined him and the Weasley twins rushing toward the front door. Loud footsteps could be heard among the insane ear-wrecking screams.

Sirius finally managed to make his mother stop ranting.  
"What a nice greeting way." – Timothy grumbled. The youngest still not dared to put down his hands, fearing the horrifying scream would go astray again.

"We were really sorry for the ruckus just then. Welcome to the Order of Phoenix. I am Lupin."-Lupin said, reaching out his hand to the group. The only girl of the group stepped up front, answered Lupin's meeting ritual with a warm smile.

"I am Lenalee. These are my colleague: Kanda, Chaozii and Timothy. We're really thankful for your help and cooperation."

Harry saw standing in front of him was a small group of four: a girl, somehow reminded him of Cho, looked the same age with him, a probably- guy looked a little bit older, a kid surely not older than eleven and a man definitely somewhere around Bill's age. All of them were wearing some kind of customized black uniform with red trimmings under their also black coat with hoods on.

For some reason, he heard his stomach clenching.

_Look at them, they even bring a child._

Lupin said they were professionals, so maybe, they were experienced with dangers.

_And they don't think you, who fought the Dark Lord and returned alive, wasn't experienced._

Shut up.

The voice knew nothing.

The 15 years old young wizard felt he was choked in his throat, yet pretending nothing was there as he gasped for breaths.

"Harry?"

Hearing the call, he turned around.

It was Ron and Hermione.

"We've just heard about Hogsmeade. It seems we will have a small talk with those have arrived. But before that, are you ok? You seem a little off."

"No, no. I'm fine." Harry waved his hand.

-Liar-

He knew the words couldn't deceive Hermione's mind. The girl said nothing, but the look she gave him was enough to let him understand that.

"Everyone has already gone upstairs. Let's go buddy."-said Ron.

"Y-yeah. Sorry."  
Harry followed the other two, stepped on the creaking wood stairs, until he heard some noise coming out.

Sobbing noises, for detail, from the drawing room.

He quickly made a turned to the room.

"You go ahead. I just want to check something."

It might just be Kreacher.

[Why did I want to check?]

[Why did I want to check alone, by myself?]

Swallow all meaningless thoughts, the kid opened the door.

The sobs were coming from , who had collapsed in Lenalee's arms, for Merlin knew how long.

"Everyone has already gone upstairs"  
Ron's words echoed.

So had the girl, who already turned into stone, and Mrs. Weasley.

In the middle of the room, standing a young white-haired male, around same age with Harry, covered himself in blood, face twisted a wicked smile.

"Of course, it could just be a boggart."  
He remembered.

As for a classical conditioning, he took out his wand, until the cold sensation the wood gave him a friendly reminder:

[The Decree for the Reasonable Restriction of Underage Sorcery]

Damn.

The kid reached to the two ladies, trying to shake them off the fear the boggart gave them.

"You two, just get out of here! Let someone else…"

"What's going on here?"

Lupin stormed in. The former DADA professor immediately understood the situation.

"_Riddikulus!_"

The spell was casted. A white water balloon appeared and replaced the bloody scene, then vanished.

"Harry, I'll take care of Molly. You go for the girl."  
As  
"It's okay. It's over. Just a stupid boggart"  
The girl still too scared.

"…Boggart?"  
"You know? That thing which would transform into anything you fear?"  
"So…it wasn't real? I'm sorry…I heard her crying…and I just want…to help."

She was trembling. Her eyes looked as if they would burst into water anytime.

"It's fine. Calm down, okay? Can you stand?"  
"Y-yeah. Thank you."

_See? She can't even handle a single boggart_

Stop it.  
[All of those meaningless words swallow them all]  
At this rate,…I may…

"Lenalee, are you alright? You look…pale."  
"I am fine, Chaozii. Sorry for making everyone wait."

With Harry's help, the two made it to their sleeping room, which had enough wide to contain all the people needed, and curious ones.

"Let's get to the point straight. We waste enough time."-Chaozzi cracked his joints.  
Sitting on the bed, beside Timothy, Lenalee began her speech.  
"Uhm…As we was explained the situation by Hogwarts's Headmaster, I want to confirme once again, that a village was under attack by some kind of machine?"

"Yes. We also get two victims."-said Fred, or George. "And we students have to return to our studies there soon."

"Okay, first of all I want you to know that…those machines were created by a magician, a really strong one, and evil. I don't know how the victims survived, though, as they always drop dead immediately, but they are dangerous and I don't want anyone here become a victim too. We can destroy them, however, but they will keep coming until they reach their goal."

"Goal?"  
Harry raised his eyebrows.

"You don't mean our school has been drag into the war between the Noah Clan and the Black Order?"

Suddenly, everyone switched their eyes to Hermione. The Exorcists group didn't believe in their ears, thinking they must have been damaged by the portrait's screams.

"What the bloody hell did you just say, Hermione?" Ron crawled away from the girl from fear.

"Come on, I am talking about the Holy War. It was mentioned from last year's History of Magic class. You guys at least pay attention. It will be in our next O.W.L test!"

"Even as an adult, I am amazed that there is someone that actual survive that class."  
Sirius commented.

"How come our war was mentioned in your class?" –asked Lenalee, in curiousity.  
"Well, it's in the textbook, but mentioned very briefly. All I know that the Head of the Noah Clan started it around 100 years ago and all magical clans that are behind the Black Order are branded 'blood traitors' by the traditionalist pure-bloods, as they help the Muggles out with their magic…There is no specific date or time, or names mentioned….And there is a law agreed by the Head of Noah Clan and International Confederation of Wizards to prevent any kind of interfere from both sides to the war, as well as any means of harm to both sides, so I didn't understand the attacks on Hogsmeade."

"Law is created to be broken down."  
Said Kanda. "Let's return to the main topic."

"Yeah. As I said about the goal, I, and professor Dumbledore personally thinks, that their main ambition is something that is hidden inside the school. Sadly, we don't know how it looks, or what it is, but it's there. That's why we will also attend school, as student for not making unnecessary fuss. The easiest way to find it is tracking its trace, as it will create strange phenomenon."-Lenalee continued.

"What kind of phenomenon?"-Harry asked.  
"We…don't know. It could be a ghost, a tree that moves on its own, a diary that writes itself, something,…"

Harry wanted to hit his head on the wall. Professor Dumbledore clearly didn't explained to

"I'm sorry to disappoint you but…all of them can be explained by magic…"-said Hermione.

"Wow…I am truly sorry…I…we are not wizards…Professor Dumbledore said we all are capable ones, but was isolated from the magic world that we…don't know much."

"That's why we're here." Hermione smiled.

"Wait, did I hear 'we'?" Ron jumped out of the mattress he was in.

"Ron! We are Perfects, remember? It's our responsibility to help people in Hogwarts out!"

"Don't worry. Follow the rule and you guys will be fine."-Joyfully said by the red-headed twin, who were playing with Timothy's tails of hair during the talk.

"Rules?" Harry confused, and somehow feared of the twin's rule.

"Not the school's rule._ Their_."

" You mean _them_?"  
Sirius began to cross his arms, let himself and Lupin flow along with his old memory about their old good days.  
"Enough with pronoun game, please?"-Annoyed Ron is annoyed.

"We don't know who they are, since they used nicknames addresses each other. We just know that they used to be Hogwarts students, and graduated a long time ago. All the school's rule-breaker groups go after that rules. The rules were simple: Be informative, be silence, be quick, be smart and be secretive. If I recall correctly, they never have their group titled, but they left their marks all over the school. Marauder's map was completed thanks to their marks. Their greatest achievement was being able to leave a pair of socks in Dumbledore's personal room as a Christmas present."

"The nicknames were Murmuring Umbrella, Scurfy Ill, Cereal Ink, Acceptable Neat."

Amazed by the rule breakers's story, the rest of the room was speechless.

Meanwhile, in an empty Hogwarts's room, where a certain mirror stood, the white-haired boy was standing in front of the mirror.

[Erised stra ehru oyt ube cafru oyt on wohsi]

His small, still completely normal left hand traced over the letters engraved on the bronze surface of the mirror.

The small kid let out a sigh and leave silently.

[Pull on the hood and keep cool]

_Let's say it's our own personal Morse code._


End file.
